RU2773784C2 - Method for cutting tubular structure on floor of drilling rig and cutting device for implementing such a method - Google Patents

Abstract

FIELD: drilling.

SUBSTANCE: method includes following stages: i) providing cutting device (100) on the floor of a drilling rig, containing cutting element (130) made without the possibility of rotation and with the possibility of progressive cutting movement through tubular structure (1); ii) placing cutting device (100) in a cutting position outside from tubular structure (1); iii) fixing the position of cutting device (100) relatively to tubular structure (1), and iv) activating cutting device (100) for cutting tubular structure (1) by means of progressive movement of at least one cutting element (130) through tubular structure (1). The invention also relates to a cutting device to be used in this method.

EFFECT: fast cutting of a tubular structure on the floor of a drilling rig compared to existing abrasive cutting methods.

15 cl, 12 dwg

Description

The technical field to which the invention belongs

The invention relates to a method for cutting a tubular structure, in particular a drill string, on the floor of a drilling rig. The invention also relates to a cutting device for use in said method.

State of the art

When performing drilling operations, in particular, work with drilling equipment, sometimes it becomes necessary to cut tubular structures, in particular casing strings, drill strings, tubing strings and risers. Various methods for cutting tubular structures have been developed. Some of the commonly used methods for cutting tubular structures on the floor of a drilling rig are abrasive cutting from the inside of the tubular structure, cutting with diamond wire, or cutting with a power saw. The tubular structure is usually cut into small pieces, which are then removed from the rig floor. Typically, cutting time on a 30-inch casing string is on the order of several hours. The problem with the above cutting methods is that they take too long. Therefore, there is a need for faster cutting methods.

Disclosure of the essence of the invention

It is an object of the present invention to eliminate or reduce at least one of the disadvantages of the prior art, or at least to provide a useful alternative to the prior art.

This problem is solved by means of a method and device with features disclosed in the description below and in the attached claims.

The invention is defined by independent claims. The dependent claims define preferred embodiments of the invention.

In a first aspect, the invention relates to a method for cutting a tubular structure, in particular a drill string, on the floor of a drilling rig, said method comprising the following steps:

- providing a cutting device on the floor of the drilling rig, containing a cutting element made without the possibility of rotation and with the possibility of carrying out translational cutting through the tubular structure;

- the location of the cutting device in the cutting position outside of the tubular structure;

- fixing the position of the cutting device relative to the tubular structure and

- activating the cutting device for cutting the tubular structure by means of a translational movement of at least one cutting element through the tubular structure.

The use of the mobile cutting device according to the invention has the following advantages.

By providing a cutting device on the rig floor that uses translational cutting instead of rotational abrasive cutting, cutting of the tubular structure on the rig floor can be performed much faster than conventional cutting methods allow. Translational cutting technology has been previously developed for underwater applications, as known from W0 2017/099607 A1. The inventor has found that such cutting can also be carried out on the floor of a drilling rig and provides a huge time saving, since, as experiments have shown, the cutting time is reduced to 5 minutes. This is different from previously described abrasive cutting methods, which can easily take up to 2 hours.

To facilitate understanding of the invention, one or more terms are defined below.

When the expression "rig floor" is used, it should be interpreted as the central part of any drilling rig (in particular, a drilling rig, however, the rig floor may also be on a ship or other floating structure), i.e. as a platform from which the drill string begins its journey into the ground. It is here that the drill pipe links are traditionally assembled, as well as the bottom hole assembly (BHA), drill heads and various other drilling tools. This is the main workplace for auxiliary workers and drillers. The floor of the drilling rig is located directly below the drilling rig or drilling rig. This floor is usually a relatively small job site where the drilling crew performs installation operations, typically adding drill pipe to the drill string or removing drill pipe from the drill string. The rig floor is the most dangerous area on a rig because heavy equipment moves across it. Drill string connections are made or dismantled on the floor of the rig, and a driller's console is installed there to control the main components of the rig.

In one embodiment of the method according to the invention, the cutting device is moved to and from the tubular structure located on the floor of the drilling rig using a crane or manipulator. The control of the cutting device in this embodiment of the method is usually carried out using a crane or manipulator, while the cutting device is suspended or mounted on a support. It is fed to a tubular structure located on the floor of the drilling rig when needed and removed when no longer needed.

In one embodiment of the method according to the invention, the cutting device is moved to and from the tubular structure located on the floor of the drilling rig using a rail system. The cutting device in this embodiment of the method is usually controlled by a rail system, i. e. the cutting device is rolled up to the tubular structure located on the floor of the drilling rig when necessary and rolled back when no longer required.

In one embodiment of the method according to the invention, the tubular structure to be cut is one of the group consisting of: casing string, drill string, tubing string and riser. These tubular structures are the most common types that may need to be cut on a rig floor. In addition to cutting these types of tubular structures, the invention also provides fast cutting of a casing string with a tubing string inside and with an intermediate layer of cement between them. Alternatively, the invention provides cutting of a riser with multiple internal casing strings and a cement-intermediate tubing string in various tubular structures.

In one embodiment of the method according to the invention, in the step of providing the cutting device, a device is provided that comprises: i) a device body configured to receive a tubular structure into its cavity; ii) an actuating device mounted on the body of the device on one side of the cavity; iii) a cutting element made without the possibility of rotation and mounted on the actuator, while the actuator with the cutting element is configured to carry out translational cutting movement through the cavity containing the tubular structure, and iv) a reaction element mounted on the opposite side from the cavity of the device body opposite the cutting element for applying a reaction force to the tubular structure during cutting. The cutting device that is used in this embodiment of the method is identical to the cutting device of WO 2017/099607 A1, only the most relevant features are used to ensure progressive cutting of the tubular structure.

In one embodiment of the method according to the invention, at the stage of providing the cutting device, a device is provided in which the reaction element forms part of an additional actuator that is configured to open and close said cavity to receive said underwater tubular structure. The cutting device that is used in this embodiment of the method is slightly more advanced. The reaction element, which forms part of the additional actuator, contributes to faster cutting, thus reducing the cutting time.

In one embodiment of the method according to the invention, at the stage of providing the cutting device, a device is provided in which the reaction element is mounted on the piston rod or threaded rod of the additional actuator or is integral with the piston rod or threaded rod of the additional actuator. The cutting device that is used in this embodiment of the method is even more advanced than the described previous embodiment. In this embodiment, faster cutting is provided.

In one embodiment of the method according to the invention, in the step of providing the cutting device, a device is provided in which the reaction element is provided with an additional cutting element directed towards the non-rotatable cutting element to assist cutting. Providing a cutting device with an additional cutting element mounted on the reaction element further increases the cutting speed.

In a second aspect, the invention relates to a cutting device for use in the method according to the invention, comprising: i) a device housing configured to receive a tubular structure in its cavity; ii) an actuating device mounted on the body of the device on one side of the cavity; iii) a cutting element made without the possibility of rotation and mounted on the actuator, while the actuator with the cutting element is configured to carry out translational cutting movement through the cavity containing the tubular structure, and iv) a reaction element mounted on the opposite side from the cavity of the device body , opposite the cutting element, for applying a reaction force to the tubular structure during cutting, while the actuator contains a hydraulic working cylinder containing a piston, which is connected by means of a piston rod to a cutting element made without the possibility of rotation, while the actuator contains an accumulator , which has a fluid connection with a hydraulic working cylinder and serves to store and release energy as needed during the translational cutting motion of the cutting element, made without the possibility of rotation. The cutting device of this embodiment of the invention provides a very efficient, fast and stable cutting of a tubular structure, since the energy is supplied much more smoothly than without a battery.

In one embodiment of the cutting device according to the invention, the accumulator is mounted in a piston rod and communicates via a channel with a hydraulic working cylinder. If the actuating device is made large for cutting thick tubular structures, there is a large space in the volume of the piston rod. This space can be successfully used to accommodate an accumulator without compromising the strength of the piston rod.

In the first embodiment, the battery is used to control the force during cutting. If proper force control is not available, there may be a risk of system failure. In order to achieve this controlled cutting, the accumulator must be connected to the low pressure side of the piston in the hydraulic working cylinder, so that the actuator works against the pressure of the accumulator during cutting, i.e. the battery dampens the cutting movement and eliminates the application of high forces when the object is weakened during cutting.

In the second version, the battery is used to increase the force during cutting. To achieve this increased cutting force, an accumulator must be connected to the high pressure side of the piston in a hydraulic working cylinder such that the pressure in the accumulator is added to the hydraulic pressure applied to the high pressure side of the piston. This option generates more force and also allows you to activate the cutting device faster.

In one embodiment, the reaction element forms part of an additional actuator that is configured to open and close said cavity to receive said tubular structure. This embodiment of the cutting device is slightly more advanced. The reaction element, which forms part of the additional actuator, contributes to faster cutting, thus reducing the cutting time.

In one embodiment, the reaction element is mounted on the piston rod or threaded rod of the additional actuator or is integral with the piston rod or threaded rod of the additional actuator. This embodiment of the cutting device is even more advanced than the previous embodiment described. In this embodiment, faster cutting is provided.

In one embodiment, the reaction element is provided with an additional cutting element directed towards the non-rotatable cutting element to assist in cutting. Providing a cutting device with an additional cutting element mounted on the reaction element further increases the cutting speed.

Brief description of the drawings

The following is a description of a preferred embodiment, by way of example, illustrated by the accompanying drawings, which show:

FIG. 1 is a perspective view of an embodiment of a cutting device according to the invention placed around a tubular structure;

FIG. 2 is the same perspective view as in FIG. 1, but the cutting element is extended to cut the tubular structure;

FIG. 3 is a top view of FIG. one;

FIG. 4 is a top view of FIG. 2;

FIG. 5-10 show various steps in an embodiment of a method for cutting a tubular structure according to the invention;

FIG. 11 is a side view of another embodiment of the cutting device according to the invention, with the cutting element retracted, and

FIG. 12 is the same side view as in FIG. 11, but the cutting element is extended to cut the tubular structure.

Implementation of the invention

Various exemplary embodiments of the subject matter of the present invention are described below. For ease of understanding, this description does not present all the design features of the actual implementation. Of course, it should be understood that in the development of each such embodiment, numerous implementation-specific decisions must be made in order to achieve the developer's specific goals, in particular regarding enforcement of system and business constraints that differ for different applications. In addition, it should be understood that such development work can be complex and time consuming, but may nonetheless be common practice for those skilled in the art using the advantages of the present invention.

The subject of the present invention is described with reference to the accompanying drawings. Various systems, structures and devices are schematically depicted in the drawings for purposes of explanation only and thus do not obscure the presentation of the present invention in detail well known to those skilled in the art. However, the accompanying drawings are included to describe and explain illustrative embodiments of the present invention. Individual terms and phrases are to be understood and interpreted as having the same meaning as those terms and phrases are understood by those skilled in the art. No specific definition of the term or phrase, i.e. a definition other than the usual and generally accepted meaning as understood by those skilled in the art is not intended to apply in the continued use of any term or phrase in this specification. If a certain term or phrase is intended to be used in a special sense, i.e. in a meaning other than that understood by those skilled in the art, such special meaning will be unambiguously indicated in the description in a definition that expressly and unconditionally provides a specific definition for the specified term or phrase.

The drawings and description show a cutting device used on the floor of a drilling rig which offers an alternative solution to existing subsea cutting solutions. An important part of the invention is to perform a purely translational cutting motion to cut a tubular structure, in particular casing, drill string, tubing string and riser, on the floor of a drilling rig. Known solutions disclose methods that require a long time, in particular cutting with diamond wire. The cutting translational motion can be performed by a variety of different devices. Only one example is shown in the drawings and the detailed description. It should be emphasized that the invention is not limited to this example.

FIG. 1 shows a perspective view of an embodiment of a cutting device according to the invention with a tubular structure installed. The cutting device 100 can be installed on the floor of the drilling rig and mounted on a device for mechanized suspension and breakout of pipes (English roughneck, not shown) or made as a stand-alone system (not shown) that can be reciprocated (for example, using rail system) along the column flange (Rotary Kelly Bushing, RKB) for each cut. Alternatively, it can be moved using a crane or manipulator (not shown). FIG. 1 shows that the tubular structure 1 is installed in the cavity 50 of the cutting device 100. The cavity 50 is formed by the device body 110 and the reaction element 140. the implementation of the translational cutting movement of the specified cutting element 130. The reaction element 140 contains an additional cutting element 145 facing the cavity, as shown in the drawing. The reaction member 140 forms the threaded rod of the threaded rod actuator, which is explained in more detail below. The cutting device 100 is also provided with a plurality of connecting rigging points 171 that allow it to be moved using a crane or other type of manipulator (not shown).

FIG. 2 shows the same perspective view as in FIG. 1, but the cutting element 130 is extended to cut the tubular structure 1. This figure shows that when the linear actuator 120 is activated, the piston rod 125, on which the cutting element 130 is mounted, extends, presses and cuts the tubular structure 1 against the cutting element 145, mounted on the reaction element 140, as shown in the drawing. FIG. 2 also shows that the reaction element 140 is part of an additional actuator 150 (actuator with a threaded rod), which also contains an axis with a gear wheel 147 driven by a motor 149. When the engine 149 is turned on, the gear wheel 147 begins to rotate and move the reaction element 140, pulling it in or out depending on the direction of rotation.

The embodiment of the cutting device shown in FIG. 1 and 2, can cut tubular structures up to 30 inches (762 mm) in diameter, and can also cut drill string joint, cemented and lined casing pipes without problems. Additional characteristics of the cutting device shown in FIG. 1 and 2:

pressure used in the hydraulic cylinder - 210 bar;

the loaded volume of the hydraulic cylinder is 160 l;

weight of the cutting device - 3500 kg; length of the cutting device - 2300 mm;

the width of the cutting device is 900 mm, and the generated force is 1000 tons.

It should be emphasized that other designs and dimensions of the cutting device are possible within the scope of the present claims if the cutting device is provided for other sizes of tubular structures.

FIG. 3 is a top view of FIG. 1. In this drawing, the first side S1 and the second, opposite side S2 of the cavity 50 are indicated. On the first side S1, a cutting element 130 is installed, and on the second side S2, a reaction element 140 with an additional cutting element 145.

FIG. 4 is a top view of FIG. 2. This drawing illustrates the situation during cutting of the tubular structure 1. The tubular structure 1 is compressed in such a way that external protrusions 1p are formed on it. The figure also shows two guides 135, one on each side of the cavity 50, which serve to guide the cutting element 130 during the cutting motion.

FIG. 5-10 show the various steps of an embodiment of a method for cutting a tubular structure according to the invention.

At the stage shown in FIG. 5, the reaction element 140 is fully exposed so that the cavity 50 is open to receive the tubular structure 1 as shown in the drawing. FIG. 6 shows the same stage, but from a different angle. In this figure it can be seen that the device body 110 has an opening 110h for receiving the reaction element 140 when it is closed, i.e. moved to hole 110h. The reaction element 140 contains a toothed rack 143 on the surface.

At the stage shown in FIG. 7, the reaction element 140 under the action of the motor 149 is drawn inward as a result of the rotation of the axis with the gear wheel 147 along the rack 143 (FIG. 6), thus closing the cavity 50.

At the stage shown in FIG. 8, the cutting of the tubular structure 1 is carried out by means of a linear actuator 120 by means of a translational cutting motion. The drawing also shows a piston rod 125 that extends from the linear actuator 110.

At the stage shown in FIG. 9, the cutting of the tubular structure 1 is completed and the reaction element 140 is withdrawn again to open the cavity 50. It can be seen that the tubular structure 1 now contains two parts, i.e. the first part 1a and the second part 1b.

FIG. 10 shows the same step as in FIG. 9, but from a different angle. In this figure, the respective parts 1a and 1b are clearly visible, as well as the cutting line 1c which separates said parts 1a and 1b. The figure also shows the above-described outer protrusions 1p.

These external projections provide a distinct advantage over known abrasive cutting methods. When lined cemented casing is cut by abrasive means and the corresponding segment is removed, it must first be secured so that the inside of the casing does not fall out while lifting said segment. Due to the flattening of the casing when using the cutting device according to the invention, such fastening is no longer required, which allows an additional significant reduction in the working time by 30-60 minutes.

FIG. 11 shows a side view of another embodiment of a cutting device according to the invention with a retractable cutting element. This step corresponds to FIG. 1. In FIG. 12 shows the same side view as in FIG. 11, but the cutting element is extended to cut the tubular structure. This step corresponds to FIG. 2. This embodiment of the cutting device 100 uses an improved linear actuator 120 comprising a working hydraulic cylinder 121 in which a piston 122 connected to a piston rod 125 reciprocates as shown in the figure. The linear actuator 120 includes an accumulator 124 to improve cutting of the tubular structure 1. The accumulator 124 is conveniently housed within the piston rod 125, which has a sufficiently large volume to suit its requirements. In this embodiment, the accumulator 124 is in fluid communication with the high pressure side of the piston 122 in the working hydraulic cylinder 121 to increase the cutting force. It should be emphasized here that other constructions are also possible, however, the construction shown in FIG. 11 and 12 is a very convenient, compact and economical solution. The cutting device shown in FIG. 11 and 12 provides very efficient, fast and stable cutting of the tubular structure because the energy is applied much more smoothly than without a battery. This assumes that the working principle of the hydraulic cylinder is known, so it is not described in detail.

The specific embodiments disclosed above are illustrative only, as the invention may be modified and implemented in other but equivalent ways, obvious to those skilled in the art benefiting from the teachings of the present invention. Thus, for example, the method steps described above may be performed in a different order. In addition, no other limitations are intended to the details of construction or appearance other than those described in the following claims. Therefore, it is obvious that the specific embodiments disclosed above can be changed or modified, and all such changes are included in the scope of the invention. Accordingly, protection is sought according to the following claims.

It should be noted that the above embodiments illustrate but do not limit the invention, and many alternative embodiments may be devised by those skilled in the art without departing from the scope of the appended claims. In the claims, any reference numbers given in parentheses should not be construed as limiting the corresponding claim. The use of the verb "comprise" and its conjugations does not preclude the presence of elements or steps other than those specified in the corresponding claim. Specifying an element in the singular does not preclude the presence of a plurality of such elements. The fact that certain measures are mentioned in mutually distinct dependent claims does not indicate that a combination of these measures cannot be used to advantage. In the claims relating to the device, when listing several means, some of these means may be implemented in the form of the same product.

Claims (27)

1. A method for cutting a tubular structure (1) on the floor of a drilling rig, including the following steps: - providing on the floor of the drilling rig a cutting device (100) containing a cutting element (130) made without the possibility of rotation and with the possibility of carrying out translational cutting movement through the tubular structure (1), - the location of the cutting device (100) in the cutting position outside of the tubular structure (1), - fixing the position of the cutting device (100) relative to the tubular structure (1) and - activating the cutting device (100) for cutting the tubular structure (1) by means of a translational movement of at least one cutting element (130) through the tubular structure (1). 2. The method according to claim 1, wherein the cutting device (100) is moved towards the tubular structure (1) and away from the tubular structure (1) along the floor of the drilling rig using a crane or manipulator. 3. Method according to claim 1, wherein the cutting device (100) is moved towards the tubular structure (1) and away from the tubular structure (1) along the floor of the drilling rig by means of a rail system. 4. The method according to any one of claims 1 to 3, wherein the tubular structure (1) to be cut is one of the group consisting of: casing, drill string, tubing string and riser. 5. A method according to any one of claims 1 to 4, wherein in the step of providing the cutting device, a device is provided that comprises: - body (110) of the device, configured to receive a tubular structure (1) into its cavity (50), - an actuating device (120) mounted on the body (110) of the device on one side (S1) of the cavity, - a cutting element (130) made without the possibility of rotation and mounted on the actuator (120), while the actuator (120) with the cutting element (130) is configured to carry out translational cutting movement through the cavity (50) containing a tubular structure ( 1), and - a reaction element (140) installed on the opposite side (S2) from the cavity (50) of the body (110) of the device opposite the cutting element (130) for applying a reaction force to the tubular structure (1) during cutting. 6. The method according to claim 5, in which, at the step of providing the cutting device (100), a device is provided in which the reaction element (140) forms part of the additional actuator (150), while said additional actuator (150) is openable and closing said cavity (50) to receive said tubular structure (1). 7. The method according to claim 6, in which at the stage of providing the cutting device (100) provide a device in which the reaction element (140) is installed on the piston rod or threaded rod of the additional actuator (150) or is made integral with the piston rod or threaded rod of the additional actuator (150). 8. The method according to any one of claims 5 to 7, wherein at the step of providing the cutting device (100), a device is provided in which the reaction element (140) is provided with an additional cutting element (145) directed towards the cutting element (130) to assist cutting. made without the possibility of rotation. 9. A cutting device (100) for use in the method according to any one of claims 1 to 4, comprising: - body (110) of the device, configured to receive a tubular structure (1) into its cavity (50), - an actuating device (120) mounted on the body (110) of the device on one side (S1) of the cavity, - a cutting element (130) made without the possibility of rotation and mounted on the actuator (120), while the actuator (120) with the cutting element (130) is configured to carry out translational cutting movement through the cavity (50) containing a tubular structure ( 1), and - a reaction element (140) installed on the opposite side (S2) from the cavity (50) of the body (110) of the device opposite the cutting element (130) for applying a reaction force to the tubular structure (1) during cutting, characterized in that the actuating device (120) contains a hydraulic working cylinder (121) containing a piston (122), which is connected by means of a piston rod (125) to a cutting element (130) made without the possibility of rotation, while the actuator (120) contains an accumulator (124) , which is in fluid communication with a hydraulic working cylinder (121) for storing and releasing energy as needed during the non-rotatable translational cutting motion of the cutting element (130). 10. Cutting device (100) according to claim 9, in which the accumulator (124) is installed inside the piston rod (125) and communicates with the hydraulic working cylinder (121) by means of a channel. 11. A cutting device (100) according to claim 10, wherein the accumulator (124) is configured to communicate with the low pressure side of the piston (122) in the hydraulic working cylinder (121). 12. A cutting device (100) according to claim 10, wherein the accumulator (124) is configured to communicate with the high pressure side of the piston (122) in the hydraulic working cylinder (121). 13. Cutting device (100) according to any one of claims 9-12, in which the reaction element (140) forms part of an additional actuator (150), which is configured to open and close said cavity (50) to receive said tubular structure ( one). 14. Cutting device (100) according to claim 13, in which the reaction element (140) is mounted on the piston rod or threaded rod of the additional actuator (150) or is integral with the piston rod or threaded rod of the additional actuator (150). 15. Cutting device (100) according to any one of claims 9 to 14, wherein the reaction element (140) is provided with an additional cutting element (145) directed towards the non-rotatable cutting element (130) to assist cutting.

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